Which is the best/proper way to declare a section that has an h2 heading and an unordered list?

The declaration of a section with an h2 heading and an unordered list is properly organized in one continuous block of HTML elements in option C. This structure effectively groups related content, indicating that the heading and the list belong together under a single thematic section.

By placing the h2 heading directly above the unordered list within the section tag, it ensures the list is clearly identified as content related to that heading. This approach provides semantic clarity, allowing both browsers and assistive technologies to understand the relationship between the heading and its corresponding list.

In contrast, the other options do not maintain this clear structural hierarchy. For instance, combining an h2 header with an ordered list or incorrectly segmenting elements, such as placing the unordered list outside of the section tag, undermines the semantic purpose of HTML tags, which aim to convey the meaning and relationship of content effectively. Thus, option C stands out as the best choice by correctly encapsulating the concept under one coherent section.